The Hammers have scored in the first-half during both their last two Premier League wins. And Lanzini, one of their key players, believes the same will be necessary to beat Swansea at the London Stadium on Saturday.
"We need to concentrate first on Swansea, which is a final for us and one we need to win, then we can concentrate on the next game," said Lanzini.
"We have started the late few games really well and we need to do the same again at Swansea, score a goal or two, then we need to keep our concentration for the whole 90 minutes.
"If we do this, we have a chance to win."